From 97177d2de527e881bc642bce37cbac3044ddb7d0 Mon Sep 17 00:00:00 2001
From: Yurii Karabas <1998uriyyo@gmail.com>
Date: Mon, 4 Sep 2023 18:45:45 +0300
Subject: [PATCH] Add hook func for sqlalchemy apply filter

---
 fastapi_filters/ext/sqlalchemy.py | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/fastapi_filters/ext/sqlalchemy.py b/fastapi_filters/ext/sqlalchemy.py
index e567eae..040099b 100644
--- a/fastapi_filters/ext/sqlalchemy.py
+++ b/fastapi_filters/ext/sqlalchemy.py
@@ -90,9 +90,9 @@ def _default_apply_filter(*_: Any) -> Any:
     raise NotImplementedError
 
 
-custom_apply_filter: ConfigVar[
-    Callable[[TSelectable, EntityNamespace, str, AbstractFilterOperator, Any], TSelectable]
-] = ConfigVar(
+ApplyFilterFunc: TypeAlias = Callable[[TSelectable, EntityNamespace, str, AbstractFilterOperator, Any], TSelectable]
+
+custom_apply_filter: ConfigVar[ApplyFilterFunc[Any]] = ConfigVar(
     "apply_filter",
     default=_default_apply_filter,
 )
@@ -104,11 +104,20 @@ def _apply_filter(
     field: str,
     op: AbstractFilterOperator,
     val: Any,
+    apply_filter: Optional[ApplyFilterFunc[TSelectable]] = None,
 ) -> TSelectable:
     custom_apply_filter_impl = custom_apply_filter.get()
 
     try:
-        cond = custom_apply_filter_impl(stmt, ns, field, op, val)
+        cond = None
+        if apply_filter:
+            try:
+                cond = apply_filter(stmt, ns, field, op, val)
+            except NotImplementedError:
+                pass
+
+        if cond is None:
+            cond = custom_apply_filter_impl(stmt, ns, field, op, val)
     except NotImplementedError:
         try:
             cond = DEFAULT_FILTERS[op](ns[field], val)
@@ -124,6 +133,7 @@ def apply_filters(
     *,
     remapping: Optional[Mapping[str, str]] = None,
     additional: Optional[EntityNamespace] = None,
+    apply_filter: Optional[ApplyFilterFunc[TSelectable]] = None,
 ) -> TSelectable:
     if isinstance(filters, FilterSet):
         filters = filters.filter_values
@@ -135,7 +145,7 @@ def apply_filters(
         field = remapping.get(field, field)
 
         for op, val in field_filters.items():
-            stmt = _apply_filter(stmt, ns, field, op, val)
+            stmt = _apply_filter(stmt, ns, field, op, val, apply_filter)
 
     return stmt
 
@@ -173,8 +183,9 @@ def apply_filters_and_sorting(
     *,
     remapping: Optional[Mapping[str, str]] = None,
     additional: Optional[EntityNamespace] = None,
+    apply_filter: Optional[ApplyFilterFunc[TSelectable]] = None,
 ) -> TSelectable:
-    stmt = apply_filters(stmt, filters, remapping=remapping, additional=additional)
+    stmt = apply_filters(stmt, filters, remapping=remapping, additional=additional, apply_filter=apply_filter)
     stmt = apply_sorting(stmt, sorting, remapping=remapping, additional=additional)
 
     return stmt